Identifying altered softball bats and their effect on performance



Progress in bat design has increased the disparity between the potential and allowed performance of baseball and softball bats. This disparity has motivated some players, particularly at the amateur softball level, to have their bats altered to increase performance. This study reviews the mechanisms contributing to bat performance and how alteration techniques take advantage of these mechanisms. The study involves 28 bats that were altered by adding weight, reducing the wall thickness, artificially breaking in the barrel, or painting a non-certified bat to appear as an approved bat. The average hitting performance of the altered bats increased by nearly 5 per cent. Bat performance was observed to improve with decreasing natural frequency and radial stiffness of the barrel. However, variations between bat performance and these measures of barrel stiffness appear to make them unreliable indicators of alteration. Three comparable bats were hit in a batting cage to measure performance change from normal use. The average performance change from the batting cage increased only 1.6 per cent. © 2008 John Wiley and Sons Asia Pte Ltd